Mesoscale Precipitation Discussion 0225
NWS Weather Prediction Center College Park MD
1012 PM EDT Sat May 04 2024

Areas affected...west-central to central TX

Concerning...Heavy rainfall...Flash flooding likely

Valid 050211Z - 050800Z

Summary...Flash flooding is likely to continue over portions of
west-central into central TX over the next 6 hours. Some
significant flash flooding will be possible, especially over
central TX, west of I-35 and south of I-20 where an additional 3
to 6+ inches is expected through 08Z.

Discussion...0145Z radar imagery over TX showed areas of
widespread thunderstorms within a messy distribution of convection
and surface boundaries. An MCV was noted over the southeastern TX
Panhandle, tracking toward the northeast, parallel to a slow
moving cold front which was preceded by a broken region of
thunderstorms. In addition, slow moving thunderstorms were noted
over central TX, north of a composite outflow boundary that
extended from near TPL, west-southwest to just north of 6R6.
Instability of 1000 to 2000+ J/kg was in place across TX,
supported by steep 700-500 mb lapse rates of 8-9 C/km as sampled
by 00Z soundings from DRT, MAF and FWD.

Large scale lift ahead of a shortwave trough, tracking east across
NM, will continue to overspread a large portion of TX overnight,
with highly divergent/diffluent flow aloft setting up over
portions of central TX, within the right entrance and left exit
regions of associated upper level jet maxima. Precipitable water
values have increased into the 1.5 to 1.7 inch range for much of
the region ahead of the cold front and southeasterly winds at 850
mb are forecast by the RAP to sustain at roughly 20-30 kt,
supporting lift atop rain-cooled air at the surface.

Eventual congealing into a more organized MCS is expected through
06Z, but with the longest residence time of heavy rainfall
occurring for the region of central TX south of I-20 and west of
I-35, where rainfall rates of 2 to 3+ in/hr will be most likely to
continue within areas of training and cell mergers. Portions of
central TX are more sensitive to flash flooding due to recent
rainfall and the addition of another 3 to 6+ inches could lead to
areas of significant flash flooding. Farther north, the track of
the MCV into southern OK may support a narrow stripe of heavier
rainfall near the slow moving frontal boundary. Farther west,
across southern portions of the Permian Basin, a supercell
tracking into Crockett and Val Verde counties is expected to
continue toward the east while convective development, along the
southwestern edge of the expected MCS, potentially leads to
training for portions of the Hill Country overnight.

Otto

ATTN...WFO...EWX...FWD...HGX...LUB...MAF...OUN...SJT...

ATTN...RFC...ABRFC...WGRFC...NWC...

LAT...LON   34449718 32719622 31439546 30899568 30559655
            30299809 30000006 30100142 30370196 31020203
            31950107 33110036